The present invention relates to a static magnetic field control method and an MRI (Magnetic Resonance Imaging) apparatus, and more specifically to a static magnetic field control method and an MRI apparatus both capable of sufficiently obtaining the effect of shaping static magnetic fields and the effect of preventing a magnetic leakage flux.
There has heretofore been known a magnetic field generator wherein leakage flux preventing auxiliary magnets are provided outside magnetic plates placed on opposite surfaces of main magnets of a static magnetic field generating magnet (see patent document 1).
[Patent Document 1] Japanese Unexamined Patent Publication No. 2003-168604.
In the conventional magnetic field generator, magnetic plates are provided on opposite surfaces of main magnets, static magnetic fields are shaped in some measure by the magnetic plates, and auxiliary magnets are provided thereon to prevent leakage flux.
However, a problem arises in that when the magnetic plates are taken off for simplification of a configuration of the magnetic field generator, the effect of shaping the static magnetic fields and the effect of preventing the leakage flux cannot be sufficiently obtained in the case of the auxiliary magnets alone.